Update gradle/actions action to v6

Author: renovate[bot]

.github/workflows/gradle.yml

@@ -21,7 +21,7 @@ jobs:
         java-version: 17
 
     - name: Set up Gradle
-      uses: gradle/actions/setup-gradle@0723195856401067f7a2779048b490ace7a47d7c # v5.0.2
+      uses: gradle/actions/setup-gradle@39e147cb9de83bb9910b8ef8bd7fff0ee20fcd6f # v6.0.1
 
     - name: Assemble and Check
       run: ./gradlew assemble check